But any male killed by the Brazilian wandering spider will die happy as its poison leaves victims with a vigorous erection.

The venom contains a neurotoxin that causes paralysis and death from asphyxiation.

But countless lives have been saved by an anti-venom drug.

Romulo Leite, a researcher at America’s Georgia Medical ­College, said: “As well as overall pain, breathing difficulties and an increase in blood pressure, males develop an extremely ­uncomfortable erection that won’t go away until the anti- venom goes to work.” Mr Leite is part of a team studying ways to adapt the spider’s toxin to treat erectile dysfunction.

He warned: “The painful ­erection is a side effect that ­everybody who gets stung by this spider will experience, along with the ­general pain and ­discomfort.

WATCH OUT: Roy Hodgson's boys will have to watch there back against these eight-legged monsters [GETTY]

“Males develop an extremely ­uncomfortable erection that won’t go away until the anti-venom goes to work”

Romulo Leite

“It is no mistake that it has been listed in the Guinness Book of Records since 2010 as the world’s most venomous spider.”

Wandering spiders can have a leg span of 5.9 inches.

One expert said they are so dangerous they make the recent UK attacks by false widows look “tame”.

England’s World Cup squad will be staying within a few miles of a Rio suburb where a single spider killed two young children.

The spiders thrive in the ­squalid shanty towns – or favelas – one of which overlooks the England team’s hotel, the £700-a-night Royal Tulip on Rio’s magnificent, white sand Sao Con­rado Beach.

CRAWLERS: False widows don't pack much of a punch when compared to Brazil's lot [ALAMY]